Answer:
13/21 of the lawn is mown.
Step-by-step explanation:
First, convert 1/3 to 7/21 by multiplying both the numerator and the denominator by 7. Then, convert 2/7 to 6/21 by multiplying both the numerator and the denominator by 3. Last, add 7/21 to 6/21 to get an answer of 13/21.
